JPH04357295A - Shield propulsion method and device - Google Patents

Abstract

PURPOSE:To reduce the friction force generated by the rotation of the material to be drilled with a cutter in a space between a partitioning wall and the cutter. CONSTITUTION:A conical or head-cut conical rotary head 124 arranged in a cylindrical space 122, which is surrounded by the inner peripheral surface 126 of a shield main frame 10 while having a diameter practically same with that of the shield main frame in the axial direction, is rotated eccentrically for movement, while being rotated by itself. The material to be drilled is compacted toward the inner peripheral surface 126 of the shield main frame 10 by contact of the rotary head 124 to the material to be drilled, and the thrust is given to the shield main frame 10 during the compaction.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to shield tunnel propulsion methods and apparatus, and more particularly to shield propulsion methods and apparatus suitable for use in tube propulsion construction methods.

0002

[Prior Art] In the pipe propulsion method, a shield is generally installed at the forefront of the pipe to be propelled, and the ground is perforated by the operation of a cutter provided on the shield, followed by a jack at the rear of the pipe. Actuation exerts a thrust force on the shield and tube, propelling them both into the drilled ground. The cutter is disposed in front of the bulkhead across the interior of the shield at a distance from the bulkhead, and when the shield and tube are being propelled, the excavated material scraped by the cutter fills the space. The reaction force from the bulkhead acts on the ground face. This reaction force and earth pressure are balanced and the face is maintained stably.

0003

[Problems to be Solved by the Invention] Conventionally, the excavated material rotates within the above-mentioned interval along with the rotation of the cutter until it reaches a discharging means such as a screw conveyor provided at the lower part of the partition wall.
It is discharged through this discharge means. Therefore, a large frictional force acts between the object to be excavated and the partition wall, increasing the load on the cutter drive device. This tendency is particularly noticeable in sandy gravel ground, so when promoting sandy gravel ground using the mud water pressurization method, the concentration of bentonite in the mud water supplied to the face is increased or the amount of mud is increased. Although this method reduces friction, it is difficult to dispose of muddy water after use. Moreover, the frictional force cannot be reduced by any construction method other than the mud water pressurization method.

By the way, since the frictional force increases in proportion to the earth pressure, in order to reduce the frictional force, it is necessary to lower the earth pressure as much as possible. However, it was not possible to lower the earth pressure below the active earth pressure, which is the limit of soil pressure in the ground, and even with the mud water pressurization method, there was a limit to how much frictional force could be lowered.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to reduce the frictional forces caused by rotating the workpiece with the cutter within the space between the bulkhead and the cutter. Another object of the present invention is to provide a shield propulsion method and apparatus that can be applied to a wide range of ground ranging from soft ground to hard ground.

[0006]

[Means for Solving the Problems] A shield propulsion method according to the present invention provides a cylindrical space surrounded by an inner circumferential surface of a shield body, the diameter of which is substantially the same in the axial direction of the shield body. A rotary head placed in the space is eccentrically rotated and rotated, and the rotary head contacts the excavated object to consolidate the excavated object toward the inner circumferential surface, during which a thrust is applied to the shield body. effect.

The rotary head has a conical or truncated conical shape with an outer diameter that gradually increases toward the rear. The rotary head is forced to rotate on its own axis due to the eccentric rotational movement, and is also rotated on its own axis by the excavated object that is in contact with the rotary head.

The shield propulsion device according to the present invention includes a cylindrical shield main body, a partition wall provided in the diametrical direction of the main body, and a space provided in front of the partition wall and surrounded by the inner peripheral surface of the shield main body. a shield body having a diameter of the inner circumferential surface substantially the same in the axial direction of the shield body and defining the cylindrical space; and a shield body rotatably supported by the partition wall and driven behind the partition wall. a crankshaft having one end connected to the mechanism and the other end extending in front of the partition wall; and a crankshaft rotatably supported by the other end of the crankshaft and disposed within the space, the outer diameter of which extends toward the rear. a progressively larger conical or truncated conical rotary head;
The apparatus includes means for discharging the excavated material from the front area of the bulkhead to the rear area thereof, and a jack located at the rear of the shield body and applying a thrust to the shield body.

The shield propulsion device according to the present invention may also be configured such that an eccentric collar connected to a drive mechanism is rotatably supported by a partition wall, and the crankshaft is rotatably supported by the eccentric collar.

0010

[Embodiment] As will be described later, the shield propulsion method according to the present invention involves eccentrically rotating a conical or truncated conical rotary head in a cylindrical space and rotating it on its own axis. During the process, it exerts a thrust force on the shield body. This shield propulsion method is the same as the shield propulsion method shown in FIG. 2 in the basic configuration except for the shape of the space.

In the shield propulsion method shown in FIG. 2, a rotary head 14 disposed in a space 12 of a shield body 10 is rotated eccentrically and rotated, and a thrust is exerted on the shield body 10 during the eccentric rotation of the rotary head. .

[0012] The rotary head 14 is connected to the shield body 10.
It is located offset by e from the center of the shield body 1.
It rotates eccentrically with respect to zero and rotates on its axis at the same time. This rotation is caused by the friction caused by the rotary head 14 coming into contact with the excavated object 16, in addition to being forced by the eccentric rotational movement.

[0013] The rotary head 14 is attached to the shield body 10.
When the excavated object 16 undergoes eccentric rotational movement and rotation within the space 12, the excavated object 16 is sandwiched between the shield body 10 and the rotary head 14, and is compacted. The portion of the excavated object 16 to be consolidated sequentially moves in the circumferential direction of the shield body 10 as the rotary head 14 eccentrically rotates. On the other hand, since the shield body 10 is moving forward under thrust, earth pressure is generated on the excavated object 16, and this earth pressure, as shown by arrow A,
It acts on the face 19 of the ground 18. Due to this reaction force B and the sequential movement of the consolidated portion in the circumferential direction, the excavated object 1
6 is pushed rearward and discharged into the shear chamber 22 through the gap 20 between the rotary head 14 and the shield body 10. The excavated object 16 is then discharged outside the mine.

Due to the eccentric rotational movement of the rotary head 14, the portion of the object 16 to be excavated to be consolidated is sequentially moved in the circumferential direction, but this is due to the rotary head 14 rolling the object 16. The excavated object 16 itself is pushed out linearly in the axial direction of the shield body 10 without rotating in the circumferential direction. In this case, the effect of pushing out the excavated object 16 increases as the earth pressure reaction force of the face 19 increases, so it brings about the opposite result from the conventional method of ejecting the excavated object while turning it with the rotation of the cutter. .

The shield propulsion device according to the present invention has the same basic configuration as the shield propulsion device 30 shown in FIG. 3 except for the shape of the space. This shield propulsion device 30 includes a shield main body 10 which is a cylindrical shield main body and has a partition wall 36 provided in the diametrical direction and a space 12 provided in front of the partition wall 36, and a space in front of the shield main body 10. 12 and a hydraulic or screw jack (not shown), known per se, which exerts a thrust on a concrete pipe 32 leading behind the shield body 10.

The space 12 in front of the partition wall 36 is surrounded by the inner peripheral surface 34 of the shield body. The shield body 10 is
A plurality of hydraulic cylinders 1 are arranged at intervals in the circumferential direction.
1 (only one is shown in the figure), the direction is corrected.

A shaft portion 39a at one end of the crankshaft 38 is supported by a pair of bearings 40 attached to the bulkhead 36, and the shaft portion 39a is supported by a reducer 42 and an electric motor 44 at one end behind the bulkhead 36. The drive mechanism 46 is key-coupled to the output shaft 43 of the speed reducer 42. On the other hand, the shaft portion 39b on the other end side of the crankshaft 38 rotatably supports the rotary head 14 via a pair of bearings 48 arranged on the rotary head 14. The crankshaft 38 is
There is an eccentricity e between the shaft portion 39a and the shaft portion 39b.

A pair of tubes 50 and 52 are attached to the lower part of the partition wall 36 at intervals in the circumferential direction.
It communicates with the shear chamber 22 located between and the partition wall 36. The pipe 50 is a liquid supply pipe for supplying liquid such as fresh water or muddy water to the front of the partition wall 36, and the pipe 52 is a liquid supply pipe for supplying excavated material 16 such as surplus water or earth and sand in the ground. This is a liquid discharge pipe for discharging together with the liquid. Excavated object 16
In addition to this, the discharge can also be carried out by a screw conveyor.

The rotary head 14 disposed within the space 12 of the shield body 10 has an internal gear 54 at a portion facing the cylindrical protrusion 37 of the partition wall 36, as shown in FIGS. 3 and 4. On the other hand, a gear 56 that meshes with the internal gear 54 is attached to the protrusion 37 of the partition wall 36, and together with the crankshaft 38, a planetary gear mechanism 58 is configured. As a result, when the crankshaft 38 rotates, the rotary head 14 undergoes an eccentric rotational movement and at the same time is forced to rotate, that is, rotate on its own axis. The planetary gear mechanism 58 may be omitted, and in this case, the rotary head 14 is rotated by the excavated object 16.

As shown in FIGS. 3 and 5, the rotary head 14 is provided with a cutter 60 at its tip. Cutter 60, in the illustrated embodiment, consists of a plurality of spokes 62 radially disposed from rotary head 14 and a plurality of bits or tips 64 on each spoke. Alternatively, the cutter 60 can be formed by a disk having at least one slit, with a plurality of bits or chips protruding forward from the slit. The cutter 60 can be omitted when the shield propulsion device 30 is propelled through soft or soft ground.

In the shield propulsion device 30 shown in FIG. 6, in order to enhance the crushing action of the rotary head 14, the inner circumferential surface 34 of the shield body 10 and the outer circumferential surface 1 of the rotary head 14 are
5 are each provided with a plurality of points 66, 68 extending in the circumferential direction, forming bits or tips. These tips 66, 68 can be spiral or radial, or can be formed by alternating a series of concave portions and convex portions.

The shield propulsion device 30 shown in FIG. 6 is provided with a sealing device 70 for the gap formed between the rotary head 14 and the partition wall 36. As shown in FIG. This sealing device 70 includes a ring 72 and a spring 74. The ring 72 is the bulkhead 36
The crankshaft 38 has an O-ring 76 disposed in the forward-facing hole so as to be movable in the axial direction of the crankshaft 38 and attached to the outer periphery of the crankshaft 38 . On the other hand, the member 78 having the internal gear 54 has an O
A ring 79 is attached to the rear of the rotary head 14, and the ring 72 is biased toward the member 78 by a spring 74, so that the ring 72 is in close contact with the member 78.

According to sealing device 70, when the sliding portion of ring 72 and/or member 78 wears, spring 74
As a result, the ring 72 is pushed forward, and the ring 72 is always in close contact with the member 78, so that a permanent sealing performance can be obtained.

In the shield propulsion device 30 shown in FIG. 3, when the electric motor 44 is operated, the crankshaft 38 is rotated.
The rotary head 14 is e.g. from the center of the shield body 10.
is rotated eccentrically. As the rotary head 14 moves eccentrically, the gear 5 of the rotary head 14
4, the meshing portion of the partition wall 36 with the gear 56 moves sequentially, so the rotary head 14 rotates about the shaft portion 39b of the crankshaft 38. In this state, when thrust is applied from the rear of the concrete pipe 32 by a jack, the shield body 10 moves forward, and the excavated object 16 excavated from the face 19 of the ground 18 is transferred to the inner peripheral surface of the rotary head 14 and the shield body 10. 34, and is pushed rearward by the reaction force applied from the face 19. The excavated object 16 discharged into the shear chamber 22 in this way
is discharged to the rear through pipe 52.

Shield propulsion device 9 shown in FIGS. 7 and 8
0 is a shield body 1 having the same configuration as shown in FIG.
0, and a rotary head 14 disposed in a space 12 at the front of the shield body 10. However, this shield propulsion device 90 includes a double eccentric mechanism 92.

The eccentric mechanism 92 includes an eccentric collar 96 rotatably supported on the partition wall 36 via a bearing 94, and the eccentric collar 96 has a sleeve 98 disposed within the eccentric collar so as to be relatively rotatable. The crankshaft 38 is rotatably supported by the sleeve 98. eccentric collar 96
A gear 100 is provided on the shield main body 1.
0, a drive mechanism 106 consisting of a reduction gear 102 and an electric motor 104 is attached, and the reduction gear 1 of this drive mechanism 106
A gear 108 fixed to the shaft of 02 meshes with the gear 100 and rotates the eccentric collar 96.

The reducer 42 of the drive mechanism 46 consisting of a reducer 42 and an electric motor 44 is fixed to a flange 99 of a sleeve 98, and the shaft portion 39a of the crankshaft 38 rotatably received in the sleeve 98 is connected to the reducer 42. It is keyed to the 42 shaft. Front shaft portion 39b of crankshaft 38
rotatably supports the rotary head 14. The sleeve 98 includes a bracket 110 that is integral with the flange 99, and one end of a swing arm 112 extending in a direction across the shield body 10 is pivotally attached to the bracket 110 by a pin 114. The other end of the swing arm 112 is pivotally connected to a bracket 116 provided on the shield body 10 by a pin 118. Due to the action of the swinging arm 112, the sleeve 98 moves eccentrically in accordance with the rotation of the eccentric collar 96, but is prevented from rotating about its own axis.

During the rotation of the crankshaft 38, the eccentric collar 9
The crankshaft 38 that supports the rotary head 14 by rotating the rotary head 6 at least once or by a predetermined angle.
The shield itself will perform an eccentric rotational movement around the center of the shield body 10. Therefore, the amount of eccentricity of the rotary head 14 with respect to the shield body 10 is increased, and the compaction exerted on the excavated object can be increased. The rotation speed of the eccentric collar 96 can be set to about 1/20 of the rotation speed of the crankshaft 38, and the rotation of the eccentric collar 96 can be controlled continuously or continuously by controlling the drive by the drive mechanism 106. Can be done intermittently.

The shield propulsion device 90 can also be implemented by rotatably supporting the crankshaft 38 on the eccentric collar 96 without providing the sleeve 98.

In FIG. 1 showing an embodiment of the shield propulsion device according to the present invention, structures that are substantially the same as those described above are denoted by the same reference numerals, and detailed description thereof will be omitted. The shield propulsion device 120 has a rotary head 124 disposed in a space 122 in front of the bulkhead 36 . The rotary head 124 has a truncated conical shape and is rotatably supported on the crankshaft 38. In the shield propulsion device 120, the conical rotary head 14 used in the above-described shield device can be used instead of the truncated conical rotary head 124.

The space 122 is located on the inner peripheral surface 12 of the shield body.
It is surrounded by 6. The inner circumferential surface 126 is the shield body 10
are formed into cylindrical surfaces having substantially the same diameter in the axial direction, and define a cylindrical space 122.

In the shield propulsion method according to the present invention, in order to enhance the consolidation effect on the excavated object, the outer diameter is increased toward the rear within the cylindrical space 122 surrounded by the inner peripheral surface 126 of the shield body 10. A conical or truncated conical rotary head that gradually increases in size is rotated eccentrically and rotated on its own axis. In the shield propulsion device according to the present invention that implements the shield propulsion method, the space 122 surrounded by the inner peripheral surface 126 of the shield body 10 is formed into a cylinder having substantially the same diameter in the axial direction of the shield body 10. On the other hand, the rotary head 14 is formed into a conical shape or a truncated conical shape whose outer diameter gradually increases toward the rear.

[0033]

[Effects of the Invention] According to the present invention, the following effects can be obtained. The greater the reaction force acting from the ground face, the greater the effect of discharging the excavated material from between the rotary head and the shield body. In other words, in the conventional construction method, in order to reduce the friction of the excavated object, the earth pressure is greater than the active earth pressure and the earth pressure reaction force is obtained as low as possible to prevent the collapse of the ground. In contrast, with the present invention, it is possible to obtain as high an earth pressure reaction force as possible within the earth pressure range below the passive earth pressure, thereby making it possible to promote while preventing the collapse of the ground. This is a much safer method of shield propulsion.

[0034] When propelling with a high earth pressure reaction force that is less than the passive earth pressure, the thrust force applied to the jack can be increased, so that the construction period can be shortened. In addition, because the ground is highly stable, for example, when propelling with pressurized water while maintaining the earth pressure balance, there is no need to pressurize with muddy water such as bentonite, and fresh water is sufficient. As a result, it is extremely economical and wastewater treatment becomes easy.

[0035] Instead of guiding the excavated material to the discharge port while rotating it within the shield body, the excavated material is compacted by the eccentric rotational movement of the rotary head and by the earth pressure reaction force, that is, the force generated by the approach of the shield body. Because it leads straight to the discharge port and because the rotary head rotates, there is little resistance to rotation of the rotary head.
Abrasion caused by excavated objects can be reduced. Moreover, the cross-sectional area of the passage for the excavated object, which is defined by the space surrounded by the inner peripheral surface of the shield body and the rotary head disposed within this space, gradually becomes smaller toward the rear. Therefore, the material to be excavated can be consolidated effectively and sufficiently.

[0036] Earth pressure can be easily controlled by simply controlling the propulsion speed using a jack, so it is easy to handle.
Easy to automate.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a front space and a rotary head of a shield propulsion device according to the present invention.

FIG. 2 is a cross-sectional explanatory diagram showing the basic configuration of a shield propulsion method.

FIG. 3 is a sectional view showing the basic configuration of the shield propulsion device.

FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a side view taken from the direction of line 5-5 in FIG. 3;

FIG. 6 is a sectional view showing the basic configuration of another shield propulsion device.

FIG. 7 is a sectional view showing the basic configuration of yet another shield propulsion device.

8 is a cross-sectional view taken along line 8-8 in FIG. 7. FIG.

[Explanation of symbols]

10　Shield body 12, 122 Space 14, 124 Rotary head 16. Excavated object 30, 90, 120 Shield propulsion device 36 Bulkhead 38 Crankshaft 46, 106 Drive mechanism 92 Eccentric mechanism 96 Eccentric collar 126 Inner peripheral surface

Claims (3)

[Claims] 1. A cylindrical space surrounded by the inner circumferential surface of the shield body, the diameter of which is substantially the same in the axial direction of the shield body, and whose outer diameter decreases toward the rear. A rotary head in the shape of a cone or truncated cone that gradually increases in size is eccentrically rotated and rotated on its own axis, and the contact of the rotary head with the object to be excavated consolidates the object to be excavated toward the inner circumferential surface. A shield propulsion method in which a thrust force is exerted on the shield body. 2. A cylindrical shield body having a partition wall provided in the diametrical direction thereof and a space provided in front of the partition wall and surrounded by an inner circumferential surface of the shield body, wherein the inner circumferential surface a shield body having substantially the same diameter in the axial direction of the shield body and defining the cylindrical space; one end rotatably supported by the bulkhead and connected to a drive mechanism behind the bulkhead; a crankshaft having the other end extending in front of the partition wall; and a conical or cut-shaped crankshaft whose outer diameter gradually increases toward the rear, the crankshaft being rotatably supported by the other end and disposed within the space. A shield propulsion device including a conical rotary head, means for discharging excavated material from a front area of the bulkhead to a rear area thereof, and a jack located at the rear of the shield body and applying thrust to the shield body. . 3. A cylindrical shield body having a partition wall provided in the diametrical direction thereof and a space provided in front of the partition wall and surrounded by an inner circumferential surface of the shield body, wherein the inner circumferential surface a shield body having substantially the same diameter in the axial direction of the shield body and defining the cylindrical space; an eccentric collar rotatably supported on the partition wall and connected to a first drive mechanism; a crankshaft rotatably supported by the eccentric collar, the crankshaft having one end connected to the second drive mechanism and the other end extending in front of the partition; and a crankshaft rotatable at the other end of the crankshaft. a conical or truncated conical rotary head whose outer diameter gradually increases toward the rear, the rotary head being supported by the bulkhead and disposed within the space; and a jack behind the shield body for applying thrust to the shield body.